Web-based Real-Time Collaboration (RTC) allows the content of a session (e.g. an on-line meeting or the like) to be synchronized in real-time among all client systems (“end points”) participating in the same session. In the area of Web applications, Web-conferences or on-line meetings present unique challenges, since HTTP (HyperText Transfer Protocol) alone does not provide a way to synchronize data among remote users connected to the same server. As a result, it is problematic to create a Web-based e-meeting application, without using requiring installation of additional technology into the Web browser program running on the end points (client systems). Requiring add-on technologies such as Java™ and ActiveX® tends to create complexities and unfamiliar barriers for users to deal with. There is therefore a need for a Web-based RTC application that does not require such Web browser add-ons.
Although HTTP is the language of the Web browser, and can be invoked using technology common to most browsers (e.g. HTML, XML, JavaScript), existing systems have not provided simple JavaScript-based RTC solutions. One possible RTC Web solution would involve end points sending messages wrapped in HTTP to a server system, while also periodically polling the server via HTTP to scan for new messages to be similarly received. Such an approach based on HTTP wrapped messages is sometimes referred to as HTTP “tunneling.” Using this type of approach, the flow of messages between end points would provide a way for all end points to stay synchronized. However, the code required to create, parse and interpret the messages typically require more than can be provided conveniently using JavaScript. There accordingly a need for a different solution that is simple enough that it can be advantageously implemented using JavaScript.
Message-based RTC systems are burdened with making sure each message is received by each end point. When an end point is disconnected, or polls too slowly, memory used to queue messages may become backed-up in the server and potentially also in the end points. To address this problem, certain defense mechanisms may be used to time-out and disconnect users. However, with the wide-spread adoption of mobile computing and communication technology, it is common for a user to experience network service drop-outs. As a result, in some cases, such time out and disconnection based defense mechanisms may be too rigid, and may operate to disconnect valid users, causing user dissatisfaction. There is accordingly a need for a solution that is relatively forgiving of user disconnects, since they are a common experience.
In many use cases, sequential messages in an e-meeting negate one another (e.g. the slide show command sequence “goToPage-5”, “goToPage-4”, “goToPage-5”). In such scenarios, regardless of the implementation, it would be more efficient to avoid sending all of the message data to all endpoints, and instead only send what is specifically needed by each endpoint. There is accordingly a need to communicate via HTTP, but without forcing the endpoints to receive redundant data.
Moreover, it is important to keep in mind the general nature of real-world applications. A desirable system should support many users who may randomly join, leave, or get disconnected from a session, at any given time. There is accordingly a need for a logical mechanism to organize the HTTP-based communication, taking into account the unique situation of each client.
For the above reasons it would be desirable to have a new system for providing Web-based real-time collaboration.